The invention generally relates to apparatuses, method, network elements, systems and programs e.g. for communication or data connection etc, wherein e.g. a session or session part may be transferred.
Session continuity includes procedures for seamlessly, i.e. without disturbing interruption, continuing a session. E.g. when a mobile station such as a user equipment, UE, moves from an old access to a new access, the session or part of the session such as data components like media components in the session should continue seamlessly in the new access. As an example, when a user equipment moves from a wireless local area network, WLAN, to a UTRAN (universal mobile telecommunications system, UMTS, terrestrial radio access network), the complete session, e.g. a session initiation protocol, SIP, session, or part of the session such as media components in the session should continue seamlessly in the new access. Further, when a session or part thereof is to be retrieved by, or transferred to, a user equipment, the session should continue.
Session continuity may also be provided in other cases, for instance including the same or similar procedures in conjunction with a call. As an example, in case of voice call continuity, VCC, a voice session may be transferred from/to circuit switched, CS, domain using VCC but a session such as a data session e.g. based on SIP, may be transferred using multimedia session continuity, MMSC, procedures. Session continuity also applies to and covers procedures where the sessions or media components in the session are transferred between multiple devices.
Multimedia session continuity, MMSC, provides procedures for session continuity using protocol mechanisms such as session initiation protocol, SIP mechanisms. An example of session continuity such as 3GPP release 8 Multimedia session continuity, MMSC, is e.g. described in TR 23.893.